1. Overview of Beam Test Benoit, Ronaldo and Eduardo Nov 8 , thanks to Steve and Bill for helping to consolidate all the information

2. Current Activities and Timeline
Meetings
Weekly coordination meetings by phone
Coordination group: Benoit, David, Luca, Ronaldo, Gary, Eduardo
Help Benoit, Ronaldo and Eduardo in the organization process
Discuss organizational matters and planning
Prepare for general VRVS meeting
Bi-weekly VRVS meetings
Involves all LAT Collaborators
Inform LAT collaborators of recent developments
Gather input from collaborators
Bi-weekly report in VRVS C&A meetings
Summary of latest activities
Benefit those who cannot be present on the beam test meetings
Timeline
By early Dec, 2005
Response from CERN whether we are approved or not
Jan, 2006
Submit a beam test plan to the LAT collaboration
> end of July, 2006
Beam test starts
Depends on CERN approval and schedule
Dec, 2006
Finalize data analysis
Aggressive schedule!

3. Beam Test Objectives Science performance verification strategy
LAT phase space is huge
MC simulation used to verify requirements by analysis
Beam test used to tune and check the simulation and aspects of the reconstruction.
Essential component of our overall strategy
Objectives
See Beam test Rationale Document LAT-TD
Undergoing update
Highest-energy performance
corrections for leakage, inter-tower gaps, and backsplash (SSD in TKR and ACD).
Electromagnetic showers (gamma, electron)
beams up to at least 100 GeV.
Check the PSF and Energy reconstruction methods.
Tagged photon beam particularly in ~GeV range.
Compare distributions of quantities related to those used in background rejection with hadron beams.
Not a direct test of end-to-end rejection -- instead, check relevant distributions
Check trigger performance (e.g., CAL-HI), comes “free” with same data
Beam Test Hardware
Impractical to put full LAT in beam
Use spares
2 TKR modules
3 or 4 CAL modules
2 to 5 ACD tiles
4 TEM modules
1 GASU (for trigger)
1 PDU (for power distribution, if available)
Primary purpose is to constrain systematic uncertainties in science analysis

4. Objectives: more details…
1. PSF and Effective Area
Measure PSF and reconstruction efficiencies (by region, angle);
check analysis and CTs; tune G4 parameters for TKR topologies.
<100 MeV to >3 GeV tagged photons on- and off-axis
2. Electromagnetic shower
Calibrate Energy and Measure Energy Resolution
Tune simulation parameters and check energy reconstruction algorithms
Check corrections near edges
Shower profiles
<100 MeV to >3 GeV tagged photons and ~1 GeV to >250 GeV electrons
3. Backsplash
Measure TKR and ACD tile multiplicities, rates and topologies from backsplash
50 GeV, 100 GeV and >150 GeV electrons
4. Hadronic shower & Background rejection
Modeling of shower topologies in the CAL;
Stubs and other TKR topologies from upward-going energy
TKR topologies; TKR-CAL matching
Compare data and MC input distributions used by classification trees for analysis of background rejection
1 to 15 GeV protons (incident in the CAL) , higher energies SPS
5. Characterize Trigger/Timing
CAL-HI trigger
use >20 GeV electron data
other useful checks with same data set. (no special runs needed)
Trigger functionality
At different rates with high energy particles
System timing
high energy beams
Data Analysis Plan
Need prioritized list of plots
re-estimate required statistics (based on needed precision)
Define minimum success as soon as possible

5. Low Energy Tagged Beam Area (PS)
Photo from document written by Michela Prest for the AGILE test beam
Tagging
Si Chambers + S3
Beam
Si Chambers + S1+S2
~ 150 cm

6. High Energy Beam Area (SPS)
Looking from the other side…
Looking from one side…
Goliath
&
David
188 cm
(if he has not grown ever since…)
XY table
(calibration unit sits here)
Looking from the top
(Courtesy of Alex Moiseev)